If you want to manage audio files on your SiteNinja CMS website, using the Blog is a good solution.
1) Create a Blog category called " Podcasts".
2) Make the category "Podcasts" a menu (click the red link icon on the Admin/summary page displaying blog categories).
3) Create 1 blog article per podcast, or add all podcasts to 1 article. See how this organization uses 1 blog article to post all newsletters for each year, http://www.sbbmwriders.org/article/2-2010-sb-bmw-riders-newsletters.
4) After you create the article, you can return to the Admin/Blog page and attached your audio files to the article.